Chapter 17: Seed Plants
Terms in this set (22)
Nonseed plant reproduction
Use fertilization as a means of reproduction
-Flagellated sperm must swim in external water to the egg
Seed plant reproduction
Use pollination as means of reproduction
-Male gametophytes are transported to to female gametophytes by wind or pollen carrier
*does not require external moisture
Means "naked seed"
-The ovules and seeds of gymosperm are exposed on a cone scale or some other comparable structure
-Type of seed plant with the same common ancestor as angiosperms (another seen plant)
Includes plants such as:
Cycads: has male and female plants that are separate plants
Ginkgoes: Aka maidenhair; have female trees that produce smelly seeds and the male trees produce ornamentals
Gnetophytes: Seed bearing plants that grow on on shrubs, trees, or vines and share similarities with gymosperms and angiosperms
Conifers: The largest group of gymnosperms that has leaves that remain on the tree through all seasons (pines, hemlocks, spruces- evergreen conifers)
The dominant sporophyte generation
-has vascular tissue that extends from the roots, through the stem, and to the needle-like leaves
-Have leathery like stems that are covered with the waxy, resinous cuticle.
Pollen cones (male pine cone)
Has scales on its slender branch that bear pollen sacs where microspores become pollen grains
Seed cones (female pine cone)
Has seeds that bear ovules that develop into winged seeds
occurs when pollen grains are windblown to the seed cones
The egg becomes a sporophyte (2n) embryo enclosed ithin the ovule, which developes the a seed coat
Angiosperms (Flowering plants)
Occur as trees, shrubs, vines, and garden plants
What are the two types of a flowering plants?
and Dicots (eudicots)
-flower parts in threes or multiples of threes
-Usually parallel venation
-Scatters bundles in stem
-Flower parts in fours or fives
-woody or herbaceous
-usually net venation
-vascular bundles in a ring
-can be woody
Pollination with flowering plants
Pollen is delivered to the stigma of the carpel
-Is sometimes accomplished by wind, but more likely by the assistance of an animal pollinator
^The pollinator acquires nutrients from the flower and inadvertently collects pollen, which takes to the next flower
Double fertilization (in flowering plants)
A mature pollen grain contains two sperm
-one fertilizes the egg and the other joins with the two polar nuclei to form endosperm (3n), which serves as food for the developing embryo
The Male Gametophyte
Meiosis in pollen sacs produce four microscope, each of which will become a two celled pollen grain.
-In flowering plants, pollen grains transfer to where it can germinate and become the mature male gametophyte
The Female Gametophyte
In the ovule, the surviving megaspore undergoes three mitotic divisions to produce seven celled (eight nuclei) structure called EMBRYO SAC.
-One of the 7 cells is an egg cell.
^The largest cell contains two polar nuclei
*The embryo sac is the mature female gametophyte
Name to differences between the life cycles of seedless vascular plants and seed plants.
-Never have cones or seeds/flowers
2.) Seed plants:
ex./ flowering plants, pine trees
The pine tree, unlike the fern, is able to reproduce sexually in a dry environment. Explain
In ferns, there is a damp environment and sperm is in life cycle (need moisture)
In pine trees, the smaller male cone makes pollen (excess sperm) and the larger female cone is fertilizer by male pollen
-Male: small and fragile
-Female: larger (curvy) and more stable
Suppose you wanted to show a friend the female gameophyte of the pine. What do you do?
Female is a seed cone that participates in fertilization
Name two innovations (aside from fruit) of the flowering plant life cycle not found on the pine tree life cycle.
1.) Double fertilization: more protected fertilization deep in the flower (more subtle difference
What is the difference between pollination and fertilization?
Pollination occurs hen pollen grains are windblown to seed cones
Fertilization is when the egg becomes a sporophyte (2n) embryo enclosed in ovule that develops into seedcoat
What is the difference between monocot and dicot flowers?
Monocots have one cotyledon, scattered bundles, and are never woody.
Dicots: have 2 cotyledons, vascular bundles in a ring, and can be woody.